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Dive into the research topics where Zafer Utkan is active.

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Featured researches published by Zafer Utkan.


Tumor Biology | 2003

Polymorphisms in the MTHFR gene are associated with breast cancer.

Emel Ergul; Ali Sazci; Zafer Utkan; N. Zafer Canturk

The methylenetetrahydrofolate reductase (MTHFR) gene is a polymorphic gene involved in folate metabolism, DNA biosynthesis, methylation and genomic integrity in actively dividing cells. The MTHFR C677T and A1298C polymorphisms are likely to play an important role in the susceptibility to breast cancer. In this case-control study, we examined the role of MTHFR C677T and A1298C polymorphisms in breast cancer patients. We genotyped 118 premenopausal women with sporadic breast cancer and 193 controls, using a PCR-RFLP method. The allele frequencies of the MTHFR 677T were 31.36% in the breast cancer cases and 28.76% in the controls. The allele frequencies of the MTHFR 1298C were 37.29% in the breast cancer subjects and 31.35% in the controls. Frequencies of MTHFR C677C, C677T and T677T were 50.8, 33.9 and 14.4% in the breast cancer patients and 48.7, 45.1 and 6.2% in the controls, respectively. The results of a χ2 analysis indicated that the MTHFR 677T allele was significantly distributed (χ2 = 7.234; p = 0.027). Likewise, the MTHFR T677T genotype showed a 2.5-fold increased risk for breast cancer and the C1298C genotype showed a 1.9-fold increased risk for breast cancer. In the compound genotypes, T677T/A1298A and C677C/C1298C showed a 4.472- and a 2.301-fold increased risk for breast cancer (OR = 4.472, p = 0.001, and OR = 2.301, p = 0.024), respectively. In conclusion, our data suggest that the MTHFR 677T, 1298C alleles, T677T, C1298C genotypes, and C677C/C1298C and T677T/A1298A compound genotypes are genetic risk factors for premenopausal women with sporadic breast cancer.


Clinical and Experimental Pharmacology and Physiology | 2000

Effects of experimental obstructive jaundice on contractile responses of dog isolated blood vessels: role of endothelium and duration of bile duct ligation.

Zafer Utkan; Tijen Utkan; Yusuf Sarioglu; Nuri N Gönüllü

1. We examined the effects of experimental obstructive jaundice caused by bile duct ligation (BDL) on vascular smooth muscle function, as well as the underlying mechanisms involved, by recording responses to noradrenaline (NA), 5‐hydroxytryptamine (5‐HT) and acetylcholine (ACh) in canine isolated renal arteries and to NA in isolated mesenteric arteries in vitro. All studies were performed 7 days after the onset of BDL in renal arteries and 3, 7 and 15 days after the onset of BDL in mesenteric arteries.


Journal of Surgical Research | 2003

Effects of caustic lye injury to the esophageal smooth muscle reactivity: In vitro study

Melih Tugay; Tijen Utkan; Zafer Utkan

PURPOSE We investigated late effects of caustic lye injury on esophageal smooth muscle reactivity in the rat model. MATERIALS AND METHODS Male Sprague-Dawley rats were divided into two groups. Through a median laparatomy incision, abdominal esophageal segment was isolated. Orogastric and gastric (via gastrotomy) catheters were placed and tied over the isolated esophageal segment. Saline (0.9%) or 50% sodium hydroxide (1 ml) solution were instilled via orogastric catheter to the isolated segment in the control and caustic esophagus (CE group) groups, respectively. Then, the esophagus was rinsed with 0.9% saline via gastric catheter. The esophagus was removed and studied in organ chambers 28 days after the operation. RESULTS Carbachol- and KCl-induced contractile responses of esophageal smooth muscle were significantly reduced in the CE group with decreased E(max) value compared with the control group. Relaxant responses to serotonin were significantly reduced in the CE group with decreased E(max) value compared with the control group. No significant differences were found in E(max) and pD(2) values for papaverine acting on esophageal strips from the two groups. CONCLUSION The results provide evidence that, a surgically created caustic injury causes impaired smooth muscle reactivity that may contribute to esophageal motor dysfunction.


Clinical Breast Cancer | 2012

Predicting the Likelihood of Nonsentinel Lymph Node Metastases in Triple Negative Breast Cancer Patients With a Positive Sentinel Lymph Node: Turkish Federation of Breast Disease Associations Protocol MF09-01

Serdar Özbaş; Vahit Ozmen; Abdullah Igci; Mahmut Muslumanoglu; Beyza Ozcinar; Mujdat Balkan; Fatih Aydogan; Tülay Canda; Omer Harmancioglu; Erol Aksaz; Bahadir M. Gulluoglu; Munire Kayahan; Cihangir Özaslan; N. Zafer Canturk; Hakan Mersin; Zafer Utkan; Savaş Koçak; Nalan Ulufi; Ayfer Kamali Polat; Oya Andacoglu; Atilla Soran

BACKGROUND Triple negative (TN) tumor has a relatively high rate of recurrence and distant metastasis, but results of studies revealed that triple positive tumor is an independent predictor of axillary lymph node involvement. Our aim was to evaluate the frequency of nonsentinel lymph node metastasis (NSLNM) involvement in operable TN breast cancer with positive sentinel lymph node (SLN) and predicting the likelihood of NSLNM in this cohort of patients by using 4 different nomograms. METHODS A total of 128 patients with TN and SLN(+) underwent complete axillary lymph node dissection in 14 different centers in Turkey. For comparison, we used our previous multicenter MF08-01 Protocol, which identified 441 patients with estrogen receptor (ER(+)) who had a positive SLN biopsy and underwent subsequent complete axillary lymph node dissection. Turkish, Cambridge, and Stanford nomograms and the Tenon Score system were used to calculate the probability of NSLNM. RESULTS Patients with TN tumor had a larger tumor size. The actual percentage of NSLN positivity was 41% in the TN group and 47.1% in patient with ER(+). The Tenon Score was ≤3.5 in 12% of patients with TN and ER(+); the area under the curve in the receiver operating characteristics curve were 0.53 and 0.59, respectively. Based on the Turkish, Cambridge, and Stanford nomograms, areas under the curve were 0.54, 0.53, and 0.61, respectively in patients with TN, and were 0.79, 0.72, and 0.70, respectively, in patients with ER(+). CONCLUSION Using the Tenon Score system underestimates NSLN positivity, and tested nomograms are not good discriminators of NSLNM in patients with TN and positive SLN.


Surgery Today | 2008

Necessity for additional incisions with the cervical Collar incision to remove retrosternal goiters

Salih Topcu; Serife Tuba Liman; Zafer Cantürk; Zafer Utkan; Zeynep Cantürk; Selin Çorak; Berrin Cetinarslan

PurposeRetrosternal goiters (RSGs) can be removed transcervically, but additional incisions are sometimes necessary. We examined the factors determining the need for additional incisions to remove an RSG goiter, based on our experience and on an algorithm.MethodsAmong 499 patients who underwent surgery for a goiter, 52 (10.4%) had an RSG removed via a collar incision. Additional incisions were necessary in 11 patients (21% of those with an RSG and 2.2% overall): a partial sternotomy in 4, total sternotomy in 5, and right thoracotomy in 2.ResultsRecurrent nerve paralysis developed in two patients and one patient had a tracheal laceration. There was no mortality. A diagnosis of adenomatous goiter was confirmed in all patients.ConclusionsAdditional incisions can be made if thyroidectomy cannot be done transcervically and if the goiter extends to the level of the aortic arch. If the thyroid gland extends below the aortic arch and the lateral diameter of the goiter is greater than 10 cm, a partial sternotomy may be required. Total sternotomy is needed when an RSG extends caudally to the azygos vein, if it is located in the retrotracheal or retroesophageal space, or if it is recurrent or ectopic. Coexisting lung disorders and goiters extending to the left atrium also require thoracotomy.


Journal of Surgical Research | 2003

Impaired gastric motility in the gastroesophageal reflux rat model: an in vitro study

Melih Tugay; Firuzan Yildiz; Zafer Utkan; Tijen Utkan; Yusuf Sarioglu

PURPOSE The present study investigated the effects of acid and mixed reflux on the responsiveness of gastric smooth muscle in the gastroesophageal reflux (GER) rat model. MATERIAL AND METHODS Three groups of rat were studied encompassing acid reflux, mixed reflux and sham operation. Acid reflux was induced by pyloric ligation (AR group) and mixed reflux was induced by jejunal ligation 1 cm distal to Treitz ligament (MR group). Similar surgical manipulations were carried out in the sham operated rats (SO group). Carbachol-, serotonin-, KCl-induced contractile response and nicotine-, sodium nitroprusside-, papaverine-induced relaxant response in isolated gastric fundus smooth muscle strips were determined using in vitro muscle technique 24 h after surgery. RESULTS Isolated gastric fundus smooth muscle contractility to serotonin, carbachol or KCl was significantly reduced in the AR and MR groups with decreased Emax and pD(2) values compared with the SO group. Relaxant responses to nicotine was significantly increased in the AR and MR groups with increased Emax and pD(2) values compared with the SO group. Sodium nitroprusside and papaverine-induced-relaxant responses were similar in all of the groups and there was no change in agonist potency. CONCLUSION The present study indicates that decreased contractile and increased nicotine-induced relaxant response of the gastric smooth muscle in the surgically created GER model. These findings suggest that impaired gastric smooth muscle reactivity at least in part may play a role in gastric dysmotility in GER.


Alcohol | 2012

Effects of chronic ethanol consumption on rat upper gastrointestinal system: Functional and histologic findings

Yusufhan Yazir; Melih Tugay; Zafer Utkan; Tijen Utkan

The purpose of the present study was to determine the effect of chronic alcohol consumption on reactivity of esophageal tunica muscularis mucosae (TMM) and lower esophageal sphincter (LES) smooth muscle. Six male rats in alcohol-fed group received ethanol (7.2% v/v) in a modified liquid diet for 4 weeks. Two control groups were used; six rats in the standard diet-fed group received rat chow and water for 4 weeks. Six rats in sucrose-fed group were given sucrose and received a liquid diet. The smooth muscle reactivity of TMM and LES strips from ethanol-fed and control animals was evaluated in organ chambers. Also histologic study was undertaken to show effects of chronic alcohol consumption. Maximum contractile responses of TMM to KCl and carbachol were decreased in the ethanol-fed group compared to the control groups. Relaxant responses to serotonin were decreased in the ethanol-fed group compared to the control groups. In TMM, isoproterenol- and papaverine-induced relaxant responses were similar in the ethanol-fed and control groups. In LES smooth muscle, relaxant responses to papaverine or isoproterenol were similar in the control groups and the ethanol-fed group. There was no change in agonist potency among the groups. The relaxation response elicited by nicotine and sodium nitroprusside (SNP) or contractile response elicited by carbachol and 80 mM KCl was decreased with maximum responses and pD(2) values, in the ethanol-fed group compared to that of the control groups in LES. Decreased nNOS immunoreactivity in myenteric plexus was found in alcohol-exposed group compared to control groups. Our findings suggest that chronic alcohol consumption impairs relaxant and contractile responses of both TMM and LES smooth muscle and it may contribute to gastroesophageal reflux commonly seen after alcohol binges.


Turkish Journal of Surgery | 2018

Relationship of functional constipation and anal-retentive behavior features

Tonguç Utku Yılmaz; Halil Ibrahim Tas; Ezgi Ucar; Cem Cerit; Altay Celebi; Sertac Ata Guler; Zafer Utkan

OBJECTIVES Constipation is the most commonly seen defecation problem and related with several environmental factors. Learning defecation is learned in the childhood anal period in which anal characteristic features appear. Problems in the anal period of childhood may affect not only the characters but also the defecation function. We aimed to evaluate the relationship between constipation and anal characteristic features of participants with functional constipation. MATERIAL AND METHODS Patients with functional constipation were included in the study according to the ROME III criteria. Patients with irritable bowel disease, slow transit constipation, outlet obstruction constipation, malignancy, and psychiatric diseases were excluded from the study. Patients filled out the Personality Belief Questionnaire, Hospital Anxiety and Depression Scale, and Obsessive Belief Questionnaire. The results were compared with healthy individuals. RESULTS A total of 47 patients with functional constipation were included in the study. The avoidant, obsessive-compulsive, antisocial, narcissistic, and paranoid personality beliefs were found to be higher in patients with constipation than in the control group. Perfectionism/certainty, importance and control, and hospital anxiety scores were found to be higher in patients with constipation than in the control group. CONCLUSION Constipation may be related to several factors, such as socioeconomic environment, emotional stress, age, and diet, among others. Here we found that anal-retentive behavior features are prominent in functional constipation. Biofeedback, which can be regarded as psychotherapy of defecation control, can be used for treatment.


The Journal of Breast Health | 2018

Scoring Idiopathic Granulomatous Mastitis: An Effective System for Predicting Recurrence?

Tonguç Utku Yılmaz; Bora Gurel; Sertac Ata Guler; Mehmet Ali Baran; Busra Ersan; Seda Duman; Zafer Utkan

Objective Idiopathic granulomatous mastitis is a breast disease without a definitive etiology. There are no definitive classifications, scoring systems or certitudes. The aim of this study is to define the factors related to the recurrence and design a scoring system. Material and Methods Patients who were admitted to the general surgery department with symptoms of granulomatous mastitis were evaluated by ultrasonography and underwent antibiotic therapy. Granulomatous mastitis is diagnosed by core biopsy and treated with steroid therapy. Patients without improvement underwent surgery and were included in the study. In total, 53 patients were included in the study. There were 8 recurrent cases. Factors related with recurrences were defined. Results Number of births over 2, duration of lactation more than 18 months, body mass index greater than 31, having fistula in physical examination, abscess collection in ultrasonographic examination, and luminal inflammation score over 2 were scored as 1. Severity score in recurrent cases were 5.1±0.6 whereas 1.9±1.0 in nonrecurrent cases. Conclusion Granulomatous mastitis score is a tool targeted at predicting the risk of recurrences. The patients with these factors are more prone for recurrences.


The Journal of Breast Health | 2018

Characteristics of Special Type Breast Tumors in Our Center

Tonguç Utku Yılmaz; Levent Trabzonlu; Sertac Ata Guler; Mehmet Ali Baran; Gökhan Pösteki; Cengiz Ercin; Zafer Utkan

Objective Breast cancer is a heterogeneous disease with different histological types. Ductal breast cancer constitutes the vast majority of the breast cancers. However limited data are present in the rest of breast cancers called special or rare type breast cancers. Here in this study, we tried to describe the clinical features of special type breast cancers in our center. Materials and Methods Retrospective descriptive study was performed in Kocaeli University School of Medicine, Department of General Surgery between January 2000 and January 2016. Women diagnosed with primary breast cancer other than ductal carcinoma were included to the study. In total, 101 patients were evaluated according to histologic types, molecular types, Tumor Node Metastasis (TNM) stages, and grades. Survival of the patients was also evaluated. Results Medullary and metaplastic types showed basal type; tubular, mucinous, micropapillary carcinoma, cribriform, lobular and apocrine tumors showed luminal type molecular pattern. Neither the existence of ductal carcinoma nor any histologic types had any effects on survival. Apocrine tumors were presented in younger ages. Conclusion Histologic types of breast cancer are closely related with the molecular types of the breast cancer. Tumor size, grade, stage of the disease can show differences among histological types which might be due to the genetic background, late onset or limited number of patients. In order to achieve more significant results, multicenter national studies are needed.

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Atilla Soran

University of Pittsburgh

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